Eyeballing theCheyenne Mountain Operations Center 2

First, is a clear picture of the rear portal (someone could drive a truck
though it), the circulator fans, and one of the smaller communications portals.
If you follow the "path" down the hillside to the right you can see where
they buried their main fiber optic cables. If you examine the area bit more
carefully (to the left) you will see a third, much smaller portal

This second picture is the communications compound on the "Roof" of the
CMOC. Notice all the AT&T Long Lines Tower, the MCI equipment, the hardened
tropo gear, and secondary or emergency egress tunnels. Look very closely
at the ground and you can see the top of the pneumatic pup up antennas. If
you scroll down off the peak you will find camouflaged tropo dishes set into
stone.